塑料模具激光精密修复技术的研究

脉冲Nd:YAG激光熔覆技术是精密修复塑料模具最有效的方法之一，激光器的电压、电流、脉冲宽度、脉冲频率与激光的扫描速度、光斑直径等工艺参数直接影响着熔覆的质量。为了综合考虑各工艺参数的影响和简化工艺调整过程，提出了重叠率的观念，建立了重叠率的计算方程。分别采用预置熔覆法和手动送丝法在低碳钢基体上熔覆Ni基合金，获得了最佳工艺参数：单脉冲能量为6.7 J，重叠率为97.4%。利用扫描电子显微镜观察了手动送丝熔覆层存在的冶金缺陷，对其产生的原因进行了初步探讨。     

Sensitivity of four foodborne moulds to essential oils from turkish spices,herbs and citrus peel

The antifungal effects of 22 essential oils from Turkish spices, herbs and citrus peel on four foodborne moulds were evaluated for fungistatic and fungicidal activity. The most active oils were wild thyme (Thymus rariflorus L) and thyme (Thymus serpyllum L). Parsley (Penloselinum sativum Hoffin) and savory (Satureja hortensis L) oils were found to be the least active oils. Rhizopus sp displayed the greatest tolerance, and the most sensitive mould was Penicillium chrysogenum. Prolonged incubations reduced the fungistatic and fungicidal effects of oils. It was concluded that some oils may be useful as mould inhibitors at food additive levels.     

模具标准件二维图形元素库的建立方法

采用模具标准件图形元素库辅助绘图是模具行业提高计算机绘图速度的基本方法之一 ,对模具标准件的参数化处理会影响到图库制做的难度。详细的介绍了在AutoCAD2000中建立模具标准件二维图形元素库的具体方法与步骤 ,按照此方法 ,其他行业的设计人员也可根据自己的需要建立合适的图库文件辅助绘图。     

连铸结晶器在线热像图绘制的方法

为实现结晶器过程可视化和辅助漏钢预报技术,提出一种等值线区域填充法快速高效绘制直观的结晶器在线热像图的方法.该方法通过离散数据网格化、等值线生成和等值多边形填充绘制云图.其中,等值线生成采用网格序列法和单元剖分法结合,避免了已往的等值线追踪和二义性问题,高效准确,实现简单.将该方法与扫描母元法相比,前者绘制云图速度快,保证了精度和质量,优于后者,且算法复杂度的分析也证明了前者时间效率较高.实际应用结果表明,该方法绘制的结晶器在线热像图能很好地反映正常和非正常情况下结晶器内部温度场的特征,可满足实际生产要求.     

热电厂集中供热——过热蒸汽在轮胎工业中的应用

阐述了热电厂集中供热提供过热蒸汽在轮胎工业中的应用,根据轮胎双模定型硫化机的硫化工艺要求,实际采用内温和外温的供汽参数和供汽方案,以及过热蒸汽减温、减压装置控制原理。     

气流紧实软复盖砂型的试验研究

本文试验研究了在砂型顶面用不同方法(盖塑料膜、喷水、喷粘土浆、撒粘土粉和细砂等)施加软复盖对砂型气流紧实效果的影响。试验表明:只要在砂型顶面形成一层不透气的软隔膜,均可提高气流紧实的效果;并改善砂型背面的松散状态。其中以复盖塑料膜最为简单可靠,软复盖的气流紧实还显著地提高低矮砂型的紧实效果。     

用石膏型精密铸造工艺制作塑料制品用锌合金模具

介绍一种用于制造塑料制品生产用锌合金模具的石膏型精密铸造工艺。首先以塑料制品样品作为原始模型，翻制石膏阴凹模，后者用来制作锌合金凸模。然后用此锌合金凸模浇注塑料制品生产用的锌合金铸型。采用这种工艺可以缩短模具生产周期，并可以降低模具的生产成本。     

Technique of pulse electrochemical finishing in molds and dies

Surface finishing is one of the most important processes in mould and die making. This process is necessary not only for smoothing the surface of die or mould, but also for removing the surface layer, which has been damaged by the preceding machining process and finally improve the performances and lifetime of moulds to a large extent. It has been reported that between 30% and 40% of the total time required to manufacture a die or mold is spent on finishing operations, most of which are performed by skilled workers employing traditional techniques. At present, key problems in mould and die finishing technology can improve the finishing efficiency, consistency and quality at reduced costs. A new and high efficiency unconventional finishing technology, pulse electrochemical finishing was introduced. Experiments were done in neutral nitrate electrolytes. The influence of electrolyte composition, intereletrode gap, finishing time, flow quality, current density, compositions of steel materials and pulse parameters on the resulting surface finishing was investigated. Results indicate that pulse parameters have important influence on operations finishing and the proper selection of pulse parameters can lead to both good smoothing efficiency and surface quality at low costs.